Rupture of the thin fibrous cap overlying the necrotic core of a vulnerable plaque is the principal cause of acute coronary syndrome. Fibrous cap rupture lies at the heart of reducing cardiovascular risk since it accounts for half of all coronar artery disease deaths and, moreover, occurs without warning in moderate-risk and asymptomatic patients. Of paramount importance to characterize and better understand the vulnerable plaque rupture mechanism is the insufficient resolution of clinically available imaging tools capable of provide high resolution morphology of the atheroma in real-time. Development of the proposed imaging sensor and its imaging method will permit identifying thin cap fibroatheromas (TCFA) and quantify coronary artery calcification with greater detail than with current imaging approaches, and will open the possibility of posing new fundamental questions related to the mechanism of TCFA rupture. Specific Aim 1 is to develop thin film acousto-optic transducer for conventional CMOS based camera systems. Based on the optical ultrasound detection method, the transducer will eliminate the requirement for many hundreds of active transducer channels, severe fabrication difficulties in electrical interconnection, and low transducer signal to noise ratio especially for the large imaging array size. Specific Aim 2 is to develop novel imaging acquisition method that allows the developed transducer with a conventional CMOS camera for high resolution ultrasound imaging. Finally, Specific Aim 3 is determine the ability of the developed acousto-optic ultrasound imaging system to identify microscopic tissue composition at high resolution in real-time. It will be used for both imaging of the morphology of the fibroatheroma and presence of microcalcifications as well as the tissue composition spectroscopy of fibrous cap, necrotic core and collagen content. The successful implementation of the proposed transducer and image acquisition method will allow an unprecedented high resolution ultrasound imaging that is impossible to achieve from conventional piezoelectric or capacitive micromachined ultrasound transducers.